BSPT vs. NPT?????

**roy365** · 04-14-2008, 06:52 PM

Ok I have an odd yet perplexing technical question. Wanting to add an aftermarket gauge i have for oil pressure. I still want the use of the OEM gauge reading (even though it acts up some) and the other one. My question is does our sender have a 1/8 BSPT (British Standard Pipe Thread) or the more common 1/8 NPT? Look at this before you ask why. http://www.nissport.com/catalog/prod...tType=Products

I have a brass 1/8 NPT tee ready for installation but this has made me wonder if i am right. Does anyone know or have any better advice?

What is the difference in the 2 threads? Will they marry up or are they way off?

**roy365** · 04-14-2008, 07:28 PM

And............got another one for ya. What about the upper radiator hose? Is it 1 & 1/4'' or 1 & 1/8''? http://www.nissport.com/catalog/prod...e=Applications

Dayco hoses says their replacement hose for the Titan is a 1 & 1/4'' end diameter, but this place acts like Nissan radiator hose uppers could be a bit smaller?

TitanBlue · 04-14-2008, 07:47 PM

Absolutely do not ever mix BSPT and NPT. I believe the angle is different. They will Mate and Leak. Don't need damaged threads! My Machinist book is at work. But I know for a fact and from an experience, they are not compatible. Never try it.

Going back to check your link.....

.....Interesting info. I'll keep this in mind.

I need to mount a Oil Temp and Water Temp Gage in my Pillar Pod. I'm in need of guidance as to where the best ports are located for each function.

So, it seems like you have all the answers to my questions. Now, just need solid confirmation....

Those are a bit pricey, but look like the quaility I'd want to use, and be willing to pay for. Excellent info Roy, hope this all works out. Interesting site.

If I remember, I'll post details of the 2 threads tomorrow night. And I'll look at the hose.

**roy365** · 04-14-2008, 08:08 PM

Quote:

Originally Posted by TitanBlue

Absolutely do not ever mix BSPT and NPT. I believe the angle is different. They will Mate and Leak. Don't need damaged threads! My Machinist book is at work. But I know for a fact and from an experience, they are not compatible. Never try it.

Going back to check your link.....

.....Interesting info. I'll keep this in mind.

I need to mount a Oil Temp and Water Temp Gage in my Pillar Pod. I'm in need of guidance as to where the best ports are located for each function.

So, it seems like you have all the answers to my questions. Now, just need solid confirmation....

Those are a bit pricey, but look like the quaility I'd want to use, and be willing to pay for. Excellent info Roy, hope this all works out. Interesting site.

If I remember, I'll post details of the 2 threads tomorrow night. And I'll look at the hose.

Ok....so I have decided to mount my water temp on the upper radiator hose. This adapter from Jegs is for 1&1/4'' SAE hose. http://www.jegs.com/i/Auto+Meter/105...0002/-1/749158
But it appears to be necked for some reason.(could be handy if ours is a bit smaller) So is our upper radiator hose 1&1/4'' SAE or is it 1&1/8''????? Only way to really know is take the hose off and mic it to see.

I went ahead and ordered one of the oil pressure adapters just to be on the safe side. I can return it, but most of all i will have it if i need it coming up soon.

Glad you are with me here on this. I am slowly but surely putting the pieces together for my installs.

Let me know if you find anything out too!!!

TitanBlue · 04-14-2008, 08:24 PM

I think I have Digital Calipers in my Truck Toolbox. I've got a bunch of them at work. I'll measure that neck tomorrow.

**roy365** · 04-14-2008, 08:30 PM

Quote:

Originally Posted by TitanBlue

I think I have Digital Calipers in my Truck Toolbox. I've got a bunch of them at work. I'll measure that neck tomorrow.

Good deal. I would go out now but it's in the 30's right now

Upper radiator inside diameter.

TitanBlue · 04-15-2008, 05:35 PM

Yep! I measured at the plastic neck, and it was about 1.365" or more exactly, 35mm. So, a 1-1/4" Adapter would be the one to get. It was a bit stretched at that point, so I would round off to it being a 1-1/4" Hose if conventional size. That adapter you found is what I'm going to order tonight. It is certainly close enough to hold fine. I don't think it will be a problem at all.

FYI:
BSPT/BSPP have a 55* Thread with Rounded Peaks and Valleys.

NPT/NPS have a 60* Thread with Flat Peaks and Valleys.

NPT is 1/8-27 vs BSP 1/8-28, 1/4-18 vs 1/4-19, 3/8-18 vs 3/8-19, 1/2-14 vs 1/2-14 (same pitch)...

TitanBlue · 04-15-2008, 05:38 PM

Now, what is the fact as to our oil temp sender thread?

Japanese companies do use British threads quite commonly. I don't know the historical reason why, but have read this many times. I'm thinking you hit it correctly, but need proof before spending the 49 bucks on that adapter.

**roy365** · 04-15-2008, 05:43 PM

Quote:

Originally Posted by TitanBlue

Yep! I measured at the plastic neck, and it was about 1.365" or more exactly, 35mm. So, a 1-1/4" Adapter would be the one to get. It was a bit stretched at that point, so I would round off to it being a 1-1/4" Hose if conventional size. That adapter you found is what I'm going to order tonight. It is certainly close enough to hold fine. I don't think it will be a problem at all.

FYI:
BSPT/BSPP have a 55* Thread with Rounded Peaks and Valleys.

NPT/NPS have a 60* Thread with Flat Peaks and Valleys.

NPT is 1/8-27 vs BSP 1/8-28, 1/4-18 vs 1/4-19, 3/8-18 vs 3/8-19, 1/2-14 vs 1/2-14 (same pitch)...

Nice!!!! I will be ordering the adapter too!!!! Hope they have a few sittin around!

**roy365** · 04-15-2008, 05:46 PM

Quote:

Originally Posted by TitanBlue

Now, what is the fact as to our oil temp sender thread?

Japanese companies do use British threads quite commonly. I don't know the historical reason why, but have read this many times. I'm thinking you hit it correctly, but need proof before spending the 49 bucks on that adapter.

Maybe they adapted to the British trades? I dunno.

I will let you know how the adapter marries up to the OEM sender's threads when it arrives. It's already ordered so it wont be long I hope.

Thanks for the help.

Justintoxicated · 04-20-2008, 10:54 PM

Check Mc Master for an adapter should only be a couple bucks.

TitanBlue · 04-21-2008, 04:49 PM

Yep, That is where I shop about 3 times a week. Compare materials too, Apples to Apples. McMaster-Carr has tons of good stuff. Huge catalog too.

**roy365** · 04-21-2008, 05:56 PM

Still waiting for my Nissport oil pressure adapter to arrive. I am anxious to see which threads we have. And not a second soon enough, as my oil pressure gauge has been acting crazy lately.

So i have the NISMO oil pressure adapter that is 1/8 NPT waiting, and I have the Nissport 1/8 BSPT on order.

Also I recieved my Autometer 1&1/4'' hose adapter for the water temp gauge too. Will be a fun day when everything comes in.